Video game systems are well known in the art and can be found in most households throughout North America. The most common of these household video game systems is that manufactured by Nintendo.RTM. under the name Nintendo Entertainment System.RTM.. This type of video game system is disclosed in U.S. Pat. No. 4,799,635 to Nakagawa and includes a game console to be connected to a television in the household which receives removable memory cartridges storing game programs to be executed by the game console.
The game console referred to above includes a game microprocessor, a graphics processor or PPU and a security system. The security system is designed to prevent the game microprocessor from executing game programs stored in unauthorized memory cartridges. In addition to program Read Only Memory ("ROM") which holds the game program, the game cartridges include a specialized chip to communicate with the security system in the game console, graphics memory communicating with the graphics processor in the game console and may include bank switching circuitry acting between the program ROM and the game microprocessor in the game console.
Because of the number of components in each memory cartridge necessary to permit the game program stored therein to be executed by the game microprocessor, the manufacturing costs of memory cartridges is significant making the memory cartridges expensive to the consumer almost to the point where the cost is prohibitive. Expense to consumers has been recognized as a concern especially in the case where changes to game consoles have been made to upgrade them, which make memory cartridges designed for earlier versions of the game consoles unusable in newer game consoles.
To satisfy consumers, interfaces to allow memory cartridge designed for one type of game console to be used in a second type of game console have been considered. An example of this type of interface is shown in U.S. Pat. No. 4,844,465 to Hibino et al. The interface has one end to receive a memory cartridge designed to operate in the first type game console and a second end to be received in the receiving port of the second type game console. Internal circuitry within the interface makes the memory cartridge electrically compatible with the second type game console while the external configuration of the interface makes the memory cartridge physically compatible with the second type game console. Although this interface allows memory cartridges made for use in game consoles which have for all purposes become obsolete, to be used with newer game consoles, the costs associated with the individual memory cartridges is still a problem and heretofore has not been addressed.
It is therefore an object of the present invention to provide a novel memory cartridge for use in a video game system.